How do I create a light streak like this?
Yes, you want to create a curve to follow the path of the light streak. You are going to go into the curve settings in the property panel and go into geometry. Increase its depth to the width that you would like the streak to be. Then apply the material of the streak based off of an opacity map with a basic color. I would choose something basic like white. You are then going to animate the curve with streak with the bevel start and bevel end option in the same geometry menu in the curve settings of the properties panel. You then need to find compositing software that you can apply glow effects too from a render layer that you rendered the object in. If it is under glass it should not matter what order you render in. If you can afford BorisFX it is great for stuff like this. You can see something basic that is relevant to what you are asking that I did with the same instructions here in this scene. https://www.dropbox.com/s/1d3844h6kvg78ym/TheRealmOfCelesbian%27sFantasyHold.mp4?dl=0